Since ancient times, natural products extracted from plants have been used for multiple purposes. Plants synthesize these products according to their natural defense mechanism against any infection or disease. Turmeric or tumeric is one of those kinds of plant-based spice which has been used for medicinal purposes historically. It has proven benefits against various health-related disorders and performs a valuable role for the body [1].

Some of its significant health benefits are listed in this article. But before that, let us discuss turmeric and its chemical composition. We will also discuss curcumin, one of its major products in detail, with medicinal properties and are widely being utilized from the past till now.

What is the health benefits of turmeric? What can turmeric cure?

Turmeric is a spice and is considered one of the most significant nutritional supplements. It is usually a rhizomatous herbaceous plant that belongs to the ginger family.

It has a bitter taste, and it is frequently used in flavoring or coloring curry powders, butter, musters, and cheeses. Due to its highly significant antioxidant properties, it is used for the storage of some food products.

Until now, more than 100 components have been extracted from turmeric. These include volatile oil from roots and many coloring agents called curcuminoids that possess antioxidant properties [2].

Turmeric consists of about 5-6.6% curcumin, less than 3.5% of volatile oils, about 9% moisture, and about 0.5% extraneous matter. Besides, there are various components responsible for giving a specific aroma to turmeric [3].

Nutritional analysis of turmeric shows that turmeric is a rich source of fat, carbohydrate, dietary fiber, and proteins. Some of the nutrient elements found in turmeric are calcium, phosphorous, sodium, iron, potassium, and niacin. 

Regarding its role in medicine and health, it is a powerful anti-inflammatory, anti-tumor and antioxidant. These properties prevent the risk of various types of cancer, protect from cellular damage, and maintain good gastrointestinal health [4, 5].

What is Curcumin?

Turmeric or curcumin? Curcumin is the primary and significant compound of turmeric, also called as diferuloylmethane. It is a polyphenolic compound and is recognized throughout the world for its potential health benefits.

In Asian countries, it has been utilized in most dishes because of its antioxidants, antimicrobial, anticancer, anti-inflammatory, and anti-mutagenic properties. Also, the yellow color of turmeric is due to the presence of curcumin in it [6].

Curcumin is available in two forms, one is keto, and the other is enol form. The enol form is more stable both in the solid and solution phases compared to the keto form. Curcumin is a potent anti-inflammatory agent which reduces inflammation in the body and can cure cancer.

Curcumin is also shown to reduce the transformation, proliferation and spread of tumors by inducing programmed cell death [7].

It has also been proved to be beneficial against many inflammatory conditions such as pain, metabolic syndrome, and hepatic and kidney disorders and in the management of degenerative eye conditions. Curcumin is now also available in several different forms like capsules, ointments, tablets, soaps, energy drinks and cosmetics [8].

14 Proven health benefits of Turmeric & Curcumin

1. Improves Brain Function

Turmeric and its primary component, curcumin, along with other phenolic compounds, show a neuroprotective effect. Studies have shown that curcumin improves and protects the survival of neurons and inhibits oxidative stress to prevent them from injury [9].

These neuroprotective characteristics also result from the changed regulation of different kinds of signaling molecules like serotonin, dopamine and norepinephrine in the brain [10].

2. Effective against depression

Major depressive disorder (MDD) is a common psychiatric disorder affecting about 16% to 20% of both developing and developed countries. According to the WHO, depression will be the second most common disease in the world.

Turmeric also fights against depression. It acts as an anti-depressant molecule. Turmeric increases the "brain-derived neurotrophic factor" (BDNF) and ultimately reverses the process of depression [11].

This molecule also promotes the secretion of neurotransmitters such as dopamine and serotonin. The release of dopamine and serotonin creates a feeling of pleasure and excitement in the body. This, in turn, helps to alleviate depression. It is also reported that curcumin fights against chronic inflammation as a result it relieves depression [12].

3. Effective against Type-2-Diabetes

Type-2 diabetes mellitus is one of the most common metabolic diseases worldwide. Studies have shown that curcumin has pharmacological properties and it delays diabetes development.

It is beneficial in the improvement of β-cell function and reduces insulin resistance. It reduces oxidative stress which plays an integral role in inflammation and in the development of type-2 diabetes [13].

Several studies showed that curcumin reduces inflammatory molecules such as tumor necrosis factor, interleukin-6 and suppresses the NF-kB signaling pathway. Curcumin inhibits the pro-inflammatory mediators in the adipose tissues [14].

Curcumin is effective against inflammation and keeps the body’s blood glucose levels in a steady-state, hence it is a powerful tool to treat type-2 diabetes. A lot of research is under the pipeline to explore more beneficial results of turmeric and turmeric supplements against type-2 diabetes [15].

4. Effective against Viral Infections

Recently, there has been a tremendous increase in the development of various drugs against microbes. Different types of antiviral drugs are being used against different types of viral infections. The use of these drugs on one side has been proved beneficial against diseases. Still, on the other, it has offered a serious threat of antimicrobial resistance, due to which these drugs are becoming ineffective against different infections [16]. 

The use of Turmeric and Curcumin offers a safe and efficient way to tackle this situation. This provides protection against microbes without causing antimicrobial resistance. Curcumin causes the inhibition of the growth of microorganisms which are the reasons for several disorders. Also, the derivatives of Curcumin have shown antiviral properties against viral cell culture like those of Influenza virus, herpes virus, and HIV [17, 18].

Turmeric tea is very effective against viral infections including flu. Curcumin helps in fighting off different viruses such as herpes virus, influenza virus, Zika virus, and chikungunya virus [19].

 Studies reported that curcumin inhibits the CHIKV and ZIKV replication pathways. ZIKV and CHIKV lose their infectivity when they are exposed to curcumin or derivatives of curcumin.

Curcumin changes the viral cells ability to infect the host cells. Curcumin also decreases the rate of viral replication through the inhibition of the viral cell binding at the host cell surface. Though the significance of curcumin of inhibiting viral infections holds significant promise to treat viral infections [20].

5. Premenstrual syndrome

Studies have reported high prevalence of premenstrual syndrome in which women experience multiple symptoms including mood and physical problems. It has been noticed that estrogen and progesterone levels become reduced premenstrually and due to this neurotransmitter changes such as dopamine levels is also decline [21].

 It is reported by the researchers that turmeric is effective against premenstrual syndrome in women. It helps in the improvement of muscle cramps and gives relief from pain. Some women experience headaches, mood swings, and bloating and it is concluded by many studies that curcumin helps in the treatment of these complications in women before periods [22].

Curcumin increases the levels of dopamine, nor-epinephrine, and serotonin and it is believed that this mechanism exerts a positive effect on premenstrual syndrome mood and behavioral symptoms.

Some physical symptoms of premenstrual syndrome are strongly connected to the pain and inflammation pathways. Studies have shown that the cyclo-oxygenase-2 enzyme (COX-2) plays an important role in the synthesis of prostaglandin E2, and this hormone takes part in the pathophysiology of premenstrual syndrome (PMS).

Curcumin down regulates the cyclooxygenase-2 gene expression and results in inhibiting the production of prostaglandin molecules [23].

Some naturopathic physicians use Vitamin B6, phytotherapies, and magnesium for the treatment of premenstrual syndrome depending on the signs and symptoms present. The addition of curcumin in the treatment showed more beneficial results with no side effects [24].

6. Potential effect against Alzheimer disease

Alzheimer's disease (AD) is the most reported and most common form of dementia and is associated with mental retardation [25].

 Turmeric has been proven effective against Alzheimer's disease. Curcumin reduces oxidative stress and inflammation and helps in the treatment of Alzheimer's disease. Some studies also suggested that curcumin prevents the formation of “amyloid-β plaques” [26].

These plaques are clumps and build up in the Alzheimer's patients and are very harmful. Curcumin helps in the breakdown of these toxic plaques and alleviates Alzheimer's disease. Different reports have indicated that curcumin plays a vital role in the pathophysiology of Alzheimer's diseases such as Aβ-signaling pathway, tau phosphorylation, oxidative stress and neuroinflammation [27].

Curcumin decreases the inflammatory response of the microglial cells of the brain and inhibits the synthesis of amyloid-beta plaques fibrils and oligomers. In addition, curcumin also reduces the neurotic abnormalities that occurred due to the formation of amyloid plaques [28].

 Furthermore, curcumin effectively reduces the oxidized proteins and inflammatory molecules such as interleukin-1β. This inflammatory molecule is considered significant in the formation of neurotic plaques in the brain. Curcumin treatment in Alzheimer patients significantly reduces the “astrocytic marker glial fibrillary acidic protein”, and soluble amyloid beta plaques and insoluble plaque burden [29].

7. Improves Heart Health

Cardiovascular disorders are one of the major health problems and the reason for the frequent number of death worldwide. Studies have reported that turmeric and specifically curcumin present in it possess a potential cardio-protective effect [30].

The use of turmeric decreases the severity of pathological changes linked to damage caused by myocardial infarction, which is a serious heart condition that is caused by a decreased blood supply to any part of the heart [31]. 

Another serious heart condition prevalent in western countries is atherosclerosis. It is the condition that causes plaque formation in the arteries, and this plaque can be mainly of cholesterol, fat, or calcium. The use of turmeric causes an increase in good quality cholesterol (HDL) and a decrease in low-quality cholesterol (LDL) [32].

Turmeric reverses heart diseases by promoting heart health via improving the endothelium function of the heart. This layer of the heart plays an essential role in blood pressure regulation and blood clotting [33].

It plays an integral role in protecting against the "age-related" loss of function, and due to this less risk of developing heart disease or cardiovascular complications. Turmeric prevents endothelial dysfunctioning and promotes heart health. Furthermore, turmeric reduces oxidative stress and inflammation and improves heart function [34].

8. Helps in the prevention and treatment of cancer

Curcumin found in turmeric has been shown to reduce the risk of different cancer types. These include gastrointestinal, breast, lung, prostate, colon and pancreatic cells cancer [35].

Turmeric can inhibit cancer progression directly or it can be utilized in chemotherapeutic treatment methods to enhance their effectiveness. There are two possible processes through which curcumin found in turmeric suppresses the progression of cancer; by suppressing angiogenesis and by inhibiting tumour growth [36].

Curcumin can be extracted from turmeric and can be utilized in dietary modification for the prevention of cancer. And research studies suggest that it is safe to use in diet [37].    

9. Effective for Arthritis patients

Turmeric has the ability to work as an anti-inflammatory agent, and this activity is utilized in the treatment of various inflammatory diseases. Arthritis is a serious autoimmune disease that causes pain in different joints of the body [38].

The exact reason behind the diseases is uncertain, and as such, there is no specific treatment available to target the fundamental causes of this disorder. This disease is very common in the older population and results from ongoing inflammatory processes [39].

About 100 different forms of arthritis is documented in the literature. The most frequent of them all is osteoarthritis and rheumatoid arthritis. The main targeted treatment approaches to arthritis is to reduce the joint pain caused by inflammation and to reduce the muscle strain [40].

The long-term use of currently available drugs is also offering different side effects like immune system disturbance. So, there is a need to find herbal therapies which possess anti-inflammatory properties with minimum risks. Turmeric, due to its unique antioxidant compounds plays a key role in the treatment of arthritis [41].

Various studies have confirmed that curcumin present in turmeric shows better improvement in arthritis patients due to its immunosuppressive, anti-inflammatory and antioxidant properties. It reduces pain, inflammation and stiffness resulting from rheumatoid arthritis and improves the health condition [42].

10.  Prevents Oxidative Damage against free radicals

Oxidative damage plays a significant role in aging and many other diseases. It consists of free radicals, and these molecules are highly reactive and have unpaired electrons and cause cellular damage [43].

Free radicals react with organic molecules, including proteins, fatty acids, and DNA. Turmeric has antioxidant potential and protects the human body from oxidative stress and free radicals. Curcumin, a significant component of Turmeric, is an antioxidant and neutralizes the free radicals and protects the body [44].

Furthermore, Curcumin enhances and boosts the body's antioxidant enzymes to play their role against oxidative stress. It blocks the free radicals and activates the human body's antioxidant defense system [45].

11. Improves liver function

The liver is the most important organ in the human body, and it plays a key role in reducing the toxicity of harmful chemicals in the body.

Different types of substances are responsible for causing hepatic problems such as viral and parasitic infections, autoimmune diseases and expulsion of various toxins and contaminants and so on. Turmeric and curcumin based therapeutic approaches have been used in this regard throughout the world [46].

Curcumin present in turmeric protects the liver from the harmful effects of various elements that cause oxidative damage in the liver due to its anti-oxidative property. This property is especially beneficial for people who have to take too many strong drugs for different health problems. Since the long use of drugs can damage the liver so use of turmeric will reduce this risk by detoxifying these chemicals [47].

12. Effective against Gastrointestinal disorders

The use of Turmeric has been incredibly effective in people suffering from gastrointestinal disorders. Such orders include inflammatory bowel diseases, a group of diseases in which the digestive tract becomes inflamed, swollen, and painful. Two main diseases which come under this category are Crohn's disease and Ulcerative colitis [48].

With regular consumption of turmeric in patients with Crohn's disease, the curcumin present in it causes a reduction in the symptoms associated with the disease i.e. forming compact stools, decreased abdominal pain, decreased cramping, and less frequent bowel movements [49].

The use of turmeric also shows protection against peptic ulcers and related complications. Curcumin present in turmeric causes an increase in mucin secretion and provides protection against any irritation [50].

When any acidic nature compound is administered to the empty stomach, it causes severe damage to the gastric mucosa lining. When it is taken along with curcumin/turmeric, it doesn't show any damage or swelling in the stomach [51].  

13. Effective against eye infections

Clinical trials on the effectiveness of curcumin for improving eye health has shown promising results.

Studies have shown that the administration of curcumin, either in the form of eye drops or by oral intake, is beneficial in many pathological disorders. It also improves eye conditions in people that experience vision loss due to damage to the optic nerve [52].

Turmeric-containing eye drops reduce the loss of the eye's retinal cells; this loss of retinal cells is the early sign of an eye disorder named glaucoma. Thus turmeric prevents glaucoma [53].

Curcumin found in Turmeric is poorly soluble, and its bioavailability is also not optimal, so for utilizing its benefits properly, there is a need to develop the mechanism or its derivatives [54].

14. Effective against lung infections

Because of the continuous and rapid increase of environmental pollutants, different respiratory disorders like bronchitis, asthma and cold coughs are increasing rapidly.

The medicines which are being used currently to treat these are not much effective and also possess various other complications as well [55].

Curcumin can offer a valuable role to treat these complications related to respiratory disorders. Different study results show that curcumin present in turmeric, being an anti-inflammatory agent, blocks the release of TNF alpha-factor and provides protection against cardiovascular and pulmonary complications [56].

It has the ability to break down the mucus from the airways of the lungs and thus makes it easy for the body to remove this mucus [57].

Also, being anti-inflammatory in nature, daily consumption of turmeric causes a reduction in the inflammation of air passage. Curcumin causes a reduction in nasal airflow resistance by alleviating nasal congestion and sneezing. All of this improves the breathing ability and relieves the coughing [58].

Conclusion

Turmeric, a plant-based spice is most often grown in Central America and Asia. This plant is also known as Indian Saffron and sometimes golden spice. It has a yellowish colour, somehow a bitter taste and has an aromatic odour.

It is reported to be a rich source of fibre and carbohydrates, fats and proteins. However, it lacks cholesterol and also contains calcium, potassium, vitamin C, phosphorous and magnesium. All of these components of turmeric make it a nutritionally rich and beneficial food product. 

Since the medicinal properties of Turmeric have been known from ancient times, so it has always been used as an effective herbal medicine.

Along with its medicinal uses, it is also being used as a food spice and food additive.

For coloring purposes, it can be added to different foods like yogurt, chicken and rice. Due to its antioxidant properties, it is also used for increasing the shelf life of food products.

Turmeric oil consisted of essential fatty acids, and it exhibits anti-mutagenic, antifungal and antibacterial properties. 

Curcumin is the natural polyphenol found in turmeric and a major part of it. It is reported that this component is derived from the rhizome of the turmeric plant.

And the yellow color of turmeric is also due to the presence of curcumin in it. Curcumin is insoluble in water and finds its main role as an active antioxidant and an anti-inflammatory agent. 

All of these beneficial properties of Turmeric and its major component make it a healthy choice for treating various kinds of health-related disorders.

However, further research is still needed to explore the additional characteristics of turmeric and to increase the effectiveness of its use in the health and nutritional sector.